SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aea312febb4d9868d688d2deab407b7c3172648457ab3c264ba720267477bc16' 
  AND token = 'xOQPaZPwyuWYQApWYWhcGl0ZdcguYFGaXF96VGHiu5M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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