SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe1016f2a61aa5752064f4dd3d949574a733b2fefa988cf99097710e05744086' 
  AND token = 'YvHm4KyX4QOj+YFk7NQK6BU2K3nPYD3AnlQ9dTGujqM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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