SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a7d69556fd13b9f0bf8ab6a3496d384457aad352a3e4a90c42512e754915605' 
  AND token = 'cmq8iwTujIeVyUOnTm3sJL86h4VbSZl0+nvZZC41ODQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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