SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd04f0210f163df4526db0b36379f6c25b3a6d18b436b526ce9f349878faca482' 
  AND token = 'eYGhR+PbQBf9wZv/La8alM+3s6hsb8YbLWQlKWJTZtY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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