SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '018526b47d54117e93f71ca701f446dfd17f94c66f1d47428032249176df6a46' 
  AND token = 'PXjV8dzVeFvajnPW3ZBddU6EeEjyvhtJ56ACUWtQ/KE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}