SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24023961b26ef1856b2036c761674589cf77fcffa454826dc0c05fcd779d8ed1' 
  AND token = 'KLfMv+WKW1iT9zncVd0NeJ22dBdqiQQbDRfnW+iJzUs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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