SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1679c6135df8b21663cbdba306758b7ab424cc2d789fc25a8642df0e29c1508e' 
  AND token = 'dxQzEUiO2y7Zn5eF92dhilPv69wtqTjrsBdEmVSEgdM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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