SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0352c84c9c04e7780cfa76a37a28444119293fc07d7847b4ad7afcb48c54c0c' 
  AND token = 'IMnTuwHapZjoisiuBECdjFA661PqIoscDVndrcVwfhs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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