SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd20244011ebca96c8e6753711c7d9a9e1b5cac5219cef3538ac0e823970a1714' 
  AND token = 'BMhRjyddZ/3IfoNofTIjaiOp1qqYpDoueRdyBgQzuDo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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