SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0031991c2154b9283978c14589605839995bdafe24a837e228e0924e097fa3d2' 
  AND token = '+53Z4bKzDimKXbfwMVQTlKaV4TSxbs2RzSUbr29YgjY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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