SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3e3be6a31b5b80297387fc53ad3eb120d16e67d5fd0170ce3d9e82476ae517ee' 
  AND token = 'rqoeq+kk2W+jgYrVEaOJ5R/n3VM+ir3ln5Nz0qxoqAw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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