SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e8e9ea4b793af8f9f21436fba6769d0ca8e83b3155d9e576bfb6efcb90f2357' 
  AND token = 'DSv+BtyQKZFbFugivo3Je4W4hDFKhitlpMQ2GZFWEV0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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