SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d7e11714cfa8e6181e5ce6403da732cfe70253d5847585ca6e949708fc857db' 
  AND token = 'qFCIOAvI9vUK0gH7meU2osmPt0jJDXd/hT7wCv+vaSc=' 
  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"
    }
  }
}