SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f490340791daeb75b276bc68eb8caf45eeb01a32239ff5129c4693c293b5e7f' 
  AND token = 'aGyTLFop66o4IAYsqK8/cWU/oWUUZaMRrHwP+TzCiBw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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