SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f443e2fa15369831c255a809771dc6c1179b4dde96c6934f3e2f22d4c8f3c9bb' 
  AND token = 'UMbg0rtZeWXTPtpfWNO6wLP1mhFJO5gOx7jMJ9yqBvE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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