SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'afe1011b1343296f33f29e36e97c68afe21e84d27a5803e44d51d00f0e00ab64' 
  AND token = 'MhXXFPxEkImUqCMkOUtRTAkmsCDLfDlsUWysBoXYXZ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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