SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e5d20c826e7906b339473f09ef3cd8ba194cb6ba0af240dad0ab10beaa529a81' 
  AND token = 'x0fktOOYScJ8kmDzuNxZN+CizQCqp7nM0Q+wky8fwVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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