SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '34cbe6318af81439fde0cc246346ed67e01e3ee410a52f137690a48dbf10559a' 
  AND token = 'IrTRXCj41vPadnqB9Xkpq1bkdalK8VpgYG5F+5HAkO8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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