SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3003697b89417026a82304b2002ad371a08cbfc6f8589e965cb3923d7d09e11e' 
  AND token = 'n88TtZoSm4GYouGE+WJVStYMruCtx8MQ23mQBzgLtmw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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