SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac47840cb6d836c255cffa5db9a9c22c8fd419a976b935c11b606efc8c4141b4' 
  AND token = 'ZiluxpxrPWI2kpYdQhW2IZ559AgbN2k0YFi6zZtKeLw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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