SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ebaadf92c92f575580b009010af93bf92944df54961a491df1a259277856deed' 
  AND token = '1Eq+jN52lA41IYEX/riW0mlwBcF8T/NVVutrHPjPeNE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00063

JSON explain

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