SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '044702a6342dc97d8e3eb99b812db6f9bd54d2a1adfa348332c3caff48bed69a' 
  AND token = 'h8W144b1PKQlMytjOTtlE5NlAfFjoOG4CxSJW6OhdgM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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