SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb687b3374c5c83943107bc13f6030e4ff61c09dc7a12b67422fc107fa100d21' 
  AND token = 'oCSJ7t8NgqkYi31aKBB4MioXxly1XQcV70SYgCejlWk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}