SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '69204248d2caa213953413fa94e7b38537a7996ea12dcdd07b1099fe301889ce' 
  AND token = 'gFsijQFGAmyuNqtgp67aQikYYzcR7x9hHT7VT9VCLvY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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