SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c4a5979d82f3ea95f03a03b31d0e21d57a5a8ba72a97024377fa5ac9b60f0a3' 
  AND token = 'tQ0JIrhIgTSM323gAQ3arA9/mDKymHkMO72f5FS3WCY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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