SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35319ec3f7091114c648decca971253c2397426e62447b5b9173b7569afddfa6' 
  AND token = 'oqQxsLR5+YmH5XD2GwvjUy3G+T2/lsKRW6APPF3wctI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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