SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dce2edfb7d9756cf5cac93ab9357fd3e7094560aa992a4902b22990c7d6b3618' 
  AND token = 'e2xGjqSIxF/ULZCkJtJ5UjM1YwvNnY7m9uUE4rhBCgc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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