SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '2f1087c120c565c59d4b61f66a5b050185b3d35ce10ad3bd038e90183f807827' 
  AND token = 'AV5XjHI5XfdVPY+8wIpBNUzPSlTPUv7KBbw524yEHdA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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