SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b236c427174b8addb34b7507501587b29a8e687cbb711a123360ec611bbc9ada' 
  AND token = 'hELKQH3lcQaKfRSkideJ9ljkRcVBsmlYdWF4p1G+D4E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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