SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0f0a7c984927451098f53ca1c18bee119e4df772cf12b567d08523baad29caed' 
  AND token = '97XLtoo8Qn0AlpddokRHKABOnV2yxa7hRPBhptW+Adc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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