SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '530ecceb5dfc7a0d93144929d591c39b15ae07414deca9dd4b72671588e3b4bb' 
  AND token = 'BM/XYJgreH+KGyfvHylLHMv+4q6fs7TOfHuXCPqUloM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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