SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61638b8eb77a6ea16a8fec752a9d98c5b2f858fd15962e6c29ec799711b3d8f2' 
  AND token = 'AYQ7jAGIAKST4XSkDlqdY+p8AlBi7Z2p/Yymn73EOrs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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