SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '13356746c9effd7c4bee03c935ca70e026f4defbd98b97604f69ab99864a469c' 
  AND token = '0cpBRDlkzSGRwArZpiRQm0vGWk+9YGqyrsQqMHTsoRM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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