SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e48a2378344d38f497414aa1e863969fb17afe68d5cec2eb04f79ec1d6383854' 
  AND token = 'qi4+vEu3hJ6rXu5v8R4bFSTzH+VmXkV8bZAGypOqtng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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