SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '443f64745352f9a722433d46306547219e6901517d08eab4bcd4fa9abdbc2d0b' 
  AND token = 'XLovW3B2jSiAipWGPq5RkcQkxSl463gJeRDwFawBiJQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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