SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '600ea542a5b93a9dde5632bb184fbf162dca4202b1284c471811757013ca3ec7' 
  AND token = 'YzZFte1/n+7Ujlatnd4u1v6UfShCOJ9njX13sqdCoGM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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