SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc622968ca1625f3633e0d89c8bf794e511fbac7a62c000d90c387ac06295e44' 
  AND token = 'iNdbNgbD9jBtwzF5IpwJUAy2ydsWlO5eKhC7u8GbD/E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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