SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '443569e9b16bc5b0642ba1538dc1784e8af335f7df4085f9f328afe99d02e768' 
  AND token = '5488Vg157q3K7TqNzdU3yEpzcHbXBZuw/tJPeiWmQRs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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