SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d17b4d4b9ba57de92a74c7becf67ede49f9bddbd313bb0b4187c2701088d982' 
  AND token = 'cqh4SUtHu0b16B48dpALE8TvKwZnKYA0UHIQEpMf5GE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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