SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ed1dca043479789d8bb8f34a14cfd5bc7a4423817d59ca2c61d08c8229e6d4e' 
  AND token = 'AG88ZWf8heP3VVzVDjIqfJQRLcn/uqOHa1/PGUHSCjQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00064

JSON explain

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