SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f784aa1d622468f28fc030f3abcbbbe84e70d3d8c3e234486a74bef9b63fc70b' 
  AND token = '4OakWOWNcAEn/ymXkt6aI5gTQzjap4AoDNLeH6qFtIs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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