SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4a378b3317dbd4a7dae8ee630cf7f854fbf9eb2854d9579b2978c94cf47e6ee' 
  AND token = 'XPPrDX8VwcVBoKJ9lL2SDIaAr9qAw+nYYWoZ+HZBSLs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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