SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4ec796ce069d12a18c9c2ec083156d5d1360e80bee7741f0ab54e0030f361d68' 
  AND token = 'JFy8xkymgO211h688Z1p/5/fzSfhI7fkuxeL5CDk0uI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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