SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4811500faee487489803e953feb5ded32c3a39ecf87f251c1ca8ccec5d644a79' 
  AND token = 'SlApEidNCkpISKOqKgAqk1PPMtLgftBx56sVkLfsG5A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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