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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ae0187f7cf577b550b88bf4b0a82a10193dd8a2909ac1b6f806f1942653fef8' 
  AND token = 'i5UL+rQhBUWUWpzr9PWMMV4CyY4ZXaFAyxpYS+ayQKA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}