SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dfae2d60e0cbc342c8925ebacf2d01e23cfd1a9afd54349bf177549c231ccb6c' 
  AND token = 'P7pMWctRIltpASn9zFnrKN00yMbCYK9XFWwJFd2zxx4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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