SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2ac664099b92253f181b05bfb13f4352c1f7e38de87fdbd97274d6e32b7ad1b' 
  AND token = 'M6O/RGlvgLCc1OJFJZhMnkEQYyUr9KUe3ZAT4eswSRQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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