SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc8b82d2a08c9be84d55a7898178a94f0da76166c7555be263836f9757d29daa' 
  AND token = 'C27J43ubVxqPf/1bPKfufVkg5ghGYFAFkmjW9BxF6j0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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