SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9726b8a93f6eb595864b4a75e858315d537b97f9a31ecf4cb34053e19d85e55a' 
  AND token = 'mI1yhKC/T0BKnwwuGw3L/B/CU7EVcxYoGnW6if6Zurw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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