SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b44c9d1e1b038ccfa43d05d7e67c57f6d8b1c7f67e676702fd8a3c430ae7a765' 
  AND token = 'GVuRKqK+MzUjn0SZ4Fgv1ZNSKnfq/BprG9S1WPIl53Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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