SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5445767dde1f18557a1fe233d18d33c5fa9f536314e3b67885c18b61368c84da' 
  AND token = '96ahQr+qJ2VtQnRJH9boGZ3FKTyAiqpE8xKCXtYZ6Ig=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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