SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8372971b3780eb4e8fdbd4395230a059583058e89f8e3fe970d0964333fc1e03' 
  AND token = 'UxWAGCvyHmQQwD51HJ9VIFizmZhsDUZYHUPqbwpULDg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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