SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61f1f8fa9e053adff6d7d8efae06f86457681632d770b415cd9a12bf07695dbc' 
  AND token = 'jcA3V34jnZF9BegKm51FpX2kAnLQLlAdh+HBYFDBbH4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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