SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '105e0f45b43991cfd72db72df521d2ed899ef9f3b597ff150a74df39c1525bca' 
  AND token = 'lSL958L2xrGP8AzgZ6pmnzccTdFZcfiN65gRr/jUefc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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