SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'df9222270a6a5eaf16cf111c0669234dc476ebe7eca37e9fe8aec1249100dfd2' 
  AND token = 'LgOpACjBlHvVeA7Uh35GfIDpQTu/Hfei7HCJ2j/Js94=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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