SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '72173835dc84ad844fb2f6a38e995f2b15185c7fdfa45836dfd24ace2da1b354' 
  AND token = 'mf2CRWTejDEUE+d8rwIDLTn63k/+kwhvzILoeQvTSDk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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