SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8cca1bf2e23206a441199ecb9347f2fff3313e181263137991244ff49c727fd3' 
  AND token = 'xQJHH6kwRQcQVrOmJWyv8aKKgfHqfbmkqtHCF0dMUSk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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