SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e41bc4c0fc591b46ff6addb284ea9c7791bc700155f5b7fd7dffa2af6dd50b63' 
  AND token = 'XmloqawNLryCcLqSYEZf8ezMJFnTx1y8+Uuj6/kDwF8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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