SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99a2245d307181b44e8fc3b542a255dbe95ef2685ccd234a15a3549f9bbb1bd5' 
  AND token = 'i2LLpOKoSo8RjSfp2pvi723lu6XHkB1kxzvKEsELD/w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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