SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ac5631d9d733f66e075b6096dcf06970e63131aa5b57a590c4a703748af616a' 
  AND token = 'mbxursdONRAU1meSzI1s2Vu1+HKKorD3x/BBlx4gNPs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00063

JSON explain

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