SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9274d6f0bc5239ee0115cf3c35b43a4d92c0882e0c75cce10c3b8c3594341787' 
  AND token = 'BTfPzLVTGNUcdvbpAzrbFGdDIEn4Qgmgtu6yWtGpdOI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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